Two major banking groups apologised to customers after technical glitches left people frozen out of their accounts.
Customers who bank with Halifax and Lloyds TSB, part of the same group, had cards rejected in shops and were left unable to use some ATMs and online services.
Meanwhile the Co-operative Bank also said it had experienced problems with its banking system, including people struggling to access online services.
Both groups said they have cleared up the underlying problems and neither could say exactly how many customers were affected.
Shopper Marc Dewhurst said he was visiting the Meadowhall centre in Sheffield when he tried to pay using his Halifax card but it was declined, despite him having the cash in his account.
He said: “Luckily I had just taken £50 out of a cash machine 15 minutes earlier. I went round to the Halifax and saw people shouting at the staff.”
A Lloyds spokesman said: “We know our customers rely on us, and we apologise for the inconvenience we have caused them.”
A Co-op spokeswoman also apologised for its problems.